title: Identification of novel functionally selective κ-opioid receptor scaffolds.
abstract: The κ-opioid receptor (KOR)-dynorphin system has been implicated in the control of affect, cognition, and motivation, and is thought to be dysregulated in mood and psychotic disorders, as well as in various phases of opioid dependence. KOR agonists exhibit analgesic effects, although the adverse effects produced by some KOR agonists, including sedation, dysphoria, and hallucinations, have limited their clinical use. Interestingly, KOR-mediated dysphoria, assessed in rodents as aversion, has recently been attributed to the activation of the p38 mitogen-activated protein kinase pathway following arrestin recruitment to the activated KOR. Therefore, KOR-selective G protein-biased agonists, which do not recruit arrestin, have been proposed to be more effective analgesics, without the adverse effects triggered by the arrestin pathway. As an initial step toward identifying novel biased KOR agonists, we applied a multifaceted screening strategy utilizing both in silico and parallel screening approaches. We identified several KOR-selective ligand scaffolds with a range of signaling bias in vitro. The arylacetamide-based scaffold includes both G protein- and β-arrestin-biased ligands, while the endogenous peptides and the diterpene scaffolds are G protein biased. Interestingly, we found scaffold screening to be more successful than library screening in identifying biased ligands. Many of the identified functionally selective ligands are potent selective KOR agonists that are reported to be active in the central nervous system. They therefore represent excellent candidates for in vivo studies aiming at determining the behavioral effects mediated by specific KOR-mediated signaling cascades.
authors.affiliation: Department of Pharmacology (K.L.W., T.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (B.L.R.), University of North Carolina, Chapel Hill, North Carolina; Departments of Psychiatry (M.-L.R, J.A.J.) and Pharmacology (J.A.J.), Columbia University, College of Physicians and Surgeons, New York, New York; New York Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York (M.-L.R., J.A.J.); Department of Pharmacognosy, University of Mississippi, University, Mississippi (R.V.B., P.R.P., J.K.Z.); and Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada (A.P.S., P.J.B.).
authors.forename: Kate L
authors.initials: KL
authors.lastname: White
authors.forename: Alex P
authors.initials: AP
authors.lastname: Scopton
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Rives
authors.forename: Ruslan V
authors.initials: RV
authors.lastname: Bikbulatov
authors.forename: Prabhakar R
authors.initials: PR
authors.lastname: Polepally
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Brown
authors.forename: Terrance
authors.initials: T
authors.lastname: Kenakin
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Javitch
authors.forename: Jordan K
authors.initials: JK
authors.lastname: Zjawiony
authors.forename: Bryan L
authors.initials: BL
authors.lastname: Roth
mesh_terms: D000081:Acetamides / Q000737:chemistry / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000737:chemistry* / Q000494:pharmacology; D019390:Arrestins / Q000378:metabolism; D003198:Computer Simulation; D062126:Databases, Chemical; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology; D004399:Dynorphins / Q000737:chemistry / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D057809:HEK293 Cells; D057166:High-Throughput Screening Assays; D006801:Humans; D008024:Ligands; D021381:Protein Transport; D017473:Receptors, Opioid, kappa / Q000819:agonists* / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D000071557:beta-Arrestins
chemical_list: D000081:Acetamides; D000701:Analgesics, Opioid; D019390:Arrestins; D004224:Diterpenes; D008024:Ligands; D017473:Receptors, Opioid, kappa; D000071557:beta-Arrestins; D004399:Dynorphins; D019204:GTP-Binding Proteins